Botulinum Toxin Formulation

ABSTRACT

Botulinum neurotoxin formulated with a hyaluronic acid carrier with increased residency time of the botulinum toxin at a subdermal location and fewer botulinum toxin induced complications or side effects.

RELATED APPLICATION

This application is related to U.S. patent application Ser. No.11/828,561 filed Jul. 27, 2007.

BACKGROUND

The present invention relates to an improved botulinum toxinformulation. In particular the present invention relates to aninjectable botulinum toxin-hyaluronic acid formulation which can beadministered with reduced local and systemic botulinum toxin inducedcomplications.

A pharmaceutical composition (synonymously a formulation or acomposition) is a formulation which contains at least one activeingredient (for example a botulinum neurotoxin) as well as, for example,one or more excipients, buffers, carriers, stabilizers, preservativesand/or bulking agents, and is suitable for administration to a humanpatient to achieve a desired effect or result. The pharmaceuticalcompositions disclosed herein can have diagnostic, therapeutic, cosmeticand/or research utility.

Hyaluronic Acid

Hyaluronic acid (also called hyaluronan or sodium hyaluronate) is anaturally occurring polysaccharide found in joints, connective tissueand the eye. Hyaluronic acid is a glycosaminoglycan (amucopolysaccharide) which is a long unbranched polysaccharide composedof repeating dimeric units of glucuronic acid and N acetyl glucosamine.U.S. Pat. Nos. 4,636,524; 4,713,448; 5,099,013, and 5,143,724 discloseparticular hyaluronic acids and methods for making them.

Hyaluronic acid has known therapeutic and cosmetic uses. For example,intra-articular use of hyaluronic acid as a viscosupplement to treatosteoarthritis joint pain is known (eg Orthovisc® (Anika), Durolane(Smith & Nephew), Hyalgan® (Sanofi), Hylastan® (Genzyme), Supartz®(Seikagaku/Smith & Nephew)), Synvisc® (Genzyme), and Euflexxa®,(Ferring)). Hyaluronic acid is also used cosmetically as an injectabledermal filler (eg Juvederm™ (Allergan)).

U.S. patent applications which disclose use of therapeutic agentformulated with a hyaluronic acid include application Ser. No.10/966,764, filed Oct. 14, 2004, application Ser. No. 11/091,977, filedMar. 28, 2005, application Ser. No. 11/354,415, Feb. 14, 2006,application Ser. No. 11/741,366, filed Apr. 27, 2007, application Ser.No. 11/828,561, filed Jul. 26, 2007, application Ser. No. 11/039,192,filed Jan. 19, 2005, application Ser. No. 11/116,698, filed Apr. 27,2005, application Ser. No. 11/695,527, filed Apr. 2, 2007, andapplication Ser. No. 11/742,350, filed Apr. 30, 2007.

Botulinum Toxin

The anaerobic, gram positive bacterium Clostridium botulinum produces apotent polypeptide neurotoxin called botulinum neurotoxin toxin whichcauses a neuroparalytic illness in humans and animals referred to asbotulism. Botulinum toxin type A is the most lethal natural biologicalagent known to man. About 50 picograms of a commercially availablebotulinum toxin type A (purified neurotoxin complex)¹ is a LD₅₀ in mice(i.e. 1 unit). One unit of BOTOX® contains about 50 picograms (about 56attomoles) of botulinum toxin type A complex. One unit (U) of botulinumtoxin is defined as the LD₅₀ upon intraperitoneal injection into femaleSwiss Webster mice weighing 18 to 20 grams each. ¹ Available fromAllergan, Inc., of Irvine, Calif. under the tradename BOTOX® in 100 unitvials)

Seven, generally immunologically distinct botulinum neurotoxins havebeen characterized, these being respectively botulinum neurotoxinserotypes A, B, C₁, D, E, F and G each of which is distinguished byneutralization with type-specific antibodies. The different serotypes ofbotulinum toxin vary in the animal species that they affect and in theseverity and duration of the paralysis they evoke. Botulinum toxinapparently binds with high affinity to cholinergic motor neurons, istranslocated into the neuron and blocks the release of acetylcholine.

Botulinum toxins have been used for the treatment of various therapeuticand cosmetic conditions. A botulinum toxin type A (Allergan, Inc.,BOTOX®) has been approved by the U.S. Food and Drug Administration forthe treatment of blepharospasm, strabismus, cervical dystonia,hyperhydrosis and glabellar lines.

The molecular weight of the neurotoxic component of a botulinum toxincomplex is about 150 kD. Botulinum toxin is typically made by theClostridial botulinum bacterium as a complex comprising the 150 kDbotulinum toxin protein molecule and associated non-toxin proteins.Thus, a botulinum toxin type A complex can be produced by Clostridialbacterium as 900 kD, 500 kD and 300 kD complex forms.

A commercially available botulinum toxin containing pharmaceuticalcomposition is sold under the trademark BOTOX® (available from Allergan,Inc., of Irvine, Calif.). BOTOX® consists of a purified botulinum toxintype A complex, albumin and sodium chloride packaged in sterile,vacuum-dried form. Each vial of BOTOX® contains about 100 units (U) ofClostridium botulinum toxin type A purified neurotoxin complex, 0.5milligrams of human serum albumin and 0.9 milligrams of sodium chloridein a sterile, vacuum-dried form without a preservative. Othercommercially available botulinum neurotoxins approved for use in humansinclude DYSPORT® (Beaufour Ipsen, Porton Down, England) XEOMIN® (MerzPharmaceuticals GmbH, Frankfurt, Germany) and MYOBLOC® (SolsticeNeurosciences, San Francisco, Calif.).

Botulinum Toxin Complications

Local and systemic complications can occur when a botulinum neurotoxinis administered (as by injection) into a muscle or a subcutaneous tissuefor a therapeutic or cosmetic purpose. Complications subsequent toinjection of a botulinum neurotoxin for a therapeutic or cosmeticpurpose can be due to diffusion of the botulinum neurotoxin from thesite of injection into adjacent muscle groups. Examples of known localcomplications upon injection of a botulinum toxin to treatblepharospasm, strabismus and cervical dystonia follow.

Blepharospasm (uncontrolled blinking) is characterized by involuntary,intermittent, forced eyelid closure. Botulinum toxin has been used totreat various types of blepharospasm, including blepharospasm induced bydrugs such as L-dopa or neuroleptics, dystonic eyelid and facial tics inpatients with Tourette syndrome, and apraxia of eyelid opening.Treatment of essential blepharospasm with a botulinum toxin requiresinjection of the neurotoxin into the orbicularis muscle. Unfortunately,the botulinum neurotoxin can diffuse out of this muscle into the deeperlevator muscle resulting in ptosis and visual field impairment that canpersist for several weeks to months. Additionally, brow ptosis can alsooccur with deeper diffusion of the botulinum neurotoxin out of theorbicularis muscle into the frontalis muscle. Although the medial aspectof the lower lid does not receive an injection, the botulinum toxin candiffuse into this area leading to a medial ectropion and chronictearing. Patients can also experience double vision if the botulinumneurotoxin diffuses into the deeper rectus muscles. Uncommonly,unintended diffusion of the botulinum toxin into the zygomaticus majormuscle occurs which can lead to an asymmetric facial expression.

Strabismus (crossed eyes) can be treated by injecting a botulinum toxininto individual rectus muscles. For example, the medial rectus musclescan be injected with a botulinum toxin under EMG guidance for treatingesotropia. Local inadvertent diffusion of the botulinum toxin into themuscle cone can lead to paralysis of other recti leading to doublevision and inadequate correction of the esotropia.

Cervical dystonia is the most common form of focal dystonia and ischaracterized by sustained abnormal postures or contractions of the neckmuscles. Deviation of the head can occur in multiple directions; turningof head (torticollis) is the most common subtype of cervical dystonia.Treatment of cervical dystonia with a botulinum toxin can improve thepatient's posture and function and to relieve associated pain. Althoughthe intent of botulinum toxin treatment is to inject into selectedmuscle group, for example the sternocleidomastoid muscle, occasionallyunder EMG guidance, local diffusion of the botulinum toxin out of themuscle area may occur causing unintentional paralysis of adjacentmuscles. Diffusion of the botulinum neurotoxin into the deep neckmuscles can cause weakness of the pharyngeal and esophageal muscles andresultant difficulty with swallowing (dysphagia) occasionally is severeenough to require a modified diet and monitoring for aspiration.Dysarthria, difficulty with speech, can also occur. Dysphagia is acommonly reported adverse event following treatment of cervical dystoniapatients with a botulinum toxin. In these patients, there are reports ofrare cases of dysphagia severe enough to warrant the insertion of agastric feeding tube. Aspiration pneumonia and death from dysphagia hasalso occurred after botulinum toxin administration.

Systemic complications upon local intramuscular injection of a botulinumtoxin have also been reported. Thus, respiratory distress following anintramuscular botulinum toxin injection can occur from excessivesystemic absorption and paralysis of the diaphragm. A number of cases ofsystemic botulism-like reaction with generalized weakness includingbulbar weakness resolved over several weeks has been reported.

Preclinical studies have demonstrated differences in local vs systemiceffects of different commercially available botulinum toxin products.Systemic effects may be due to escape of the intramuscularlyadministered botulinum toxin into the circulation.

What is therefore needed is a botulinum toxin formulation of which thebotulinum toxin therein shows a reduced tendency to diffuse from thesite of administration upon local (i.e. intramuscular or subcutaneous)injection of the botulinum toxin formulations, thereby reducingcomplications and side effects upon botulinum toxin administration for atherapeutic or cosmetic purpose.

SUMMARY

The present invention meets this need and provides a botulinum toxinformulated with a polymeric carrier. The formulation is injected as adepot and shows reduced diffusion of the botulinum toxin from theinjection thereby reducing potential local and systemic botulinum toxininduced complications or side effects.

DEFINITIONS

As used herein, the words or terms set forth below have the followingdefinitions.

“About” means that the item, parameter or term so qualified encompassesa range of plus or minus ten percent above and below the value of thestated item, parameter or term.

“Administration” or “to administer” means the step of giving (i.e.administering) a pharmaceutical composition to a subject. Thepharmaceutical compositions disclosed herein are “locally administered”(local administration), that is administered at or in the vicinity ofthe site at which a therapeutic result or outcome is desired. Forexample to treat an peripheral condition by peripheral administration ofa viscous formulation. Sustained release” means release of an activeagent (such as a botulinum neurotoxin) over a period of about seven daysor more, while “extended release” means release of an active agent overa period of time of less than about seven days.

“Botulinum toxin” means a botulinum neurotoxin type A, B, C, D, E, F orG as either pure toxin (i.e. the about 150 kiloDalton molecular weightneurotoxic component) or as a botulinum toxin complex (about 300 toabout 900 kiloDaltons molecular weight), including recombinant,chimeric, hybrid, retargeted, and amino acid sequence modified botulinumneurotoxins, but excluding botulinum toxins which are not neurotoxinssuch as the cytotoxic botulinum toxins C₂ and C₃.

“Entirely free (i.e. “consisting of” terminology) means that within thedetection range of the instrument or process being used, the substancecannot be detected or its presence cannot be confirmed, or that thecondition, complication or side effect does not exist.

“Essentially free” (or “consisting essentially of”) means that onlytrace amounts of the substance can be detected, or that the condition,complication or side effect is experienced by a patient for less than10% to 20% of the time.

“Local administration” means administration (i.e. by a subcutaneous,intramuscular, subdermal, intradermal, subcutaneous, intra-organ [eginjected into the bladder wall or into the body of the prostate] ortransdermal route) of a pharmaceutical agent to or to the vicinity of atarget tissue, muscle or subdermal location by a non-systemic route.Thus, local administration excludes systemic (i.e. to the bloodcirculation system) routes of administration, such as intravenous ororal administration. Peripheral administration means administration tothe periphery (i.e. to a location on or within a face, limb, trunk orhead of a patient) as opposed to a visceral or gut (i.e. to the viscera)administration.

“Pharmaceutical composition” means a formulation in which an activeingredient (the active agent) can be a botulinum neurotoxin. The word“formulation” means that there is at least one additional ingredient inthe pharmaceutical composition besides the active agent. Apharmaceutical composition is therefore a formulation which is suitablefor diagnostic or therapeutic administration (i.e. by subdermal orintramuscular injection) to a subject, such as a human patient.

“Substantially free” means present at a level of less than one percentby weight of the pharmaceutical composition, or that the condition,complication or side effect is experienced by a patient less than 50% ofthe time.

“Sustained release” means release of an active agent (such as atriamcinolone) over a period of about seven days or more, while“extended release” means release of an active agent over a period oftime of less than about seven days.

“Viscous carrier” means a biocompatible compound which when formulatedwith a botulinum neurotoxin provides upon in vivo local injection of theformulation a depot from which the botulinum toxin is released inamounts such that the extent of diffusion of the botulinum toxin awayfrom the site of the local injection and/or the amount of the botulinumtoxin which diffuses away from the site of local injection issignificantly reduced as evidenced by a substantial reduction ofbotulinum toxin complications, as compared to the incidence of botulinumtoxin complications which occur upon injection of a botulinum toxin(such as BOTOX®, DYSPORT®, XEOMIN® and MYOBLOC®) which does not comprisea viscous carrier.

All the viscosity values set forth herein were determined at 25° C.(unless another temperature is specified). Additionally, all theviscosity values set forth herein were determined at a shear rate ofabout 0.1/second (unless another shear rate is specified).

Our invention is a pharmaceutical composition comprising a botulinumneurotoxin and a viscous carrier for the botulinum neurotoxin. Theviscous carrier can be selected from the group of viscous carriersconsisting of hyaluronic acid, carbomer, polyacrylic acid, cellulosepolycarbophil, polyvinylpyrrolidone, gelatin, dextrin, polysaccharide,polyacrylamide, polyvinyl alcohol, polyvinyl acetate, chitosans,algenates and derivatives and mixtures thereof. Preferably, the viscouscarrier is a hyaluronic acid, such as a non-cross linked hyaluronic acidor a cross linked hyaluronic acid. The hyaluronic acid can be apolymeric hyaluronic acid with a molecular weight between about 10,000Daltons and about 20 million Daltons. The concentration of thehyaluronic acid in the formulation (in the pharmaceutical composition)can be between about 1 wt % and about 10 wt %, such as between about 0.1wt % and about 1 wt %.

The pharmaceutical composition can have a viscosity of between about1000 cps and about 300,000 cps at 25° C., at a shear rate of 0.1/secondor between about 100 cps and about 1,000 cps at 25° C., at a shear rateof 0.1/second.

A detailed embodiment of our invention is a pharmaceutical compositioncomprising a botulinum neurotoxin and a cross linked, polymeric,hyaluronic acid carrier for the botulinum neurotoxin, wherein thepolymeric hyaluronic acid has a molecular weight between about 10,000Daltons and about 20 million Daltons, the concentration of the polymerichyaluronic acid in the formulation is between about 0.1 wt % and about 1wt % and the viscosity of the pharmaceutical composition is betweenabout 100 cps and about 1,000 cps at 25° C., at a shear rate of about0.1/second. The botulinum neurotoxin is preferably a botulinumneurotoxin type A.

Our invention also encompasses a method for treating a disease orcondition in a human patient by administering to the patient apharmaceutical composition comprising a botulinum neurotoxin and aviscous carrier for the botulinum neurotoxin, wherein the patientexperiences significantly fewer complications due to the botulinum toxinthan occur upon administration of a botulinum toxin formulation whichdoes not comprise a viscous carrier. The administering can be carriedout by local subdermal injection of the pharmaceutical composition. Thedisease or condition treated can be, for example, a dystonia (such ascervical dystonia), blepharospasm, strabismus, spasticity, movementdisorder, headache, migraine, hyperhydrosis, overactive bladder,prostate disorder, articular pathology, arthritis, facial wrinkles, andglabellar lines. The complications experienced at a lower incidence canbe local complications such as ptosis, brow ptosis, visual fieldimpairment, double vision, ectropion, tearing, asymmetric facialexpression, dysphagia, and muscle weakness, or systemic complicationsselected from the group of system complications consisting ofrespiratory distress, generalized weakness, dry mouth, nausea, headache,constipation and vertigo. Importantly, the patient can experiences nocomplications during any ten day period up to six months after theadministration. Furthermore, the patient can experience during any tenday period up to six months after the administration a complicationwhich persists, as reported by the patient, for only 10% to 50% of theperiod of time the same complication is experienced by the patient uponadministration of a botulinum toxin formulation which is injected intothe patient at the same location, to treat the same disease orcondition, and which contains the same amount of the botulinum toxin,but which does not comprise a viscous carrier acid.

Our invention also includes a process for making a pharmaceuticalcomposition, the process comprising the steps of preparing apharmaceutical composition comprising a botulinum neurotoxin and aviscous carrier for the botulinum neurotoxin by mixing together thebotulinum neurotoxin and the viscous carrier, as well as the product bythe this process.

DRAWINGS

FIG. 1 is a schematic drawing showing the rat hind leg muscles. In FIG.1 A is the vastus lateralis (VL) muscle, B is the vastus intermediusmuscle (VI), C is the gastrocnemius muscle, and D is the soleus muscle.

FIG. 2 is a photograph showing an injection of the labeled biologiccompound of Example 3 entering the tripennate gastrocnemius lateralis(MGL) portion of the rat gastrocnemius muscle.

FIG. 3 is a two dimensional magnetic resonance image taken 40 minutesafter the FIG. 2 injection oriented longitudinal through thegastrocnemius muscle to show the MGL and unipennate gastrocnemiusmedialis (MGM) muscle groups in each leg. The right leg was injectedwith the hyaluronic acid/albumin-gadolinium complex, while the left legwith injected with just the albumin-gadolinium. FIG. 3 shows that theleft leg had a diffuse spread of the albumin-gadolinium complex (bluecolor) throughout the MGL muscle and cross-over to the adjacent MGMmuscle, whereas the right leg showed little or no diffusion of thealbumin-gadolinium complex (blue color) from the injection site.

DESCRIPTION

The present invention is based on the discovery of a botulinum toxinformulation from which the botulinum toxin exhibits reduced diffusionfrom the site of injection, as compared to known aqueous botulinum toxinformulations, with out fewer side effects or toxin inducedcomplications.

The botulinum toxin formulation we developed comprises a botulinum toxinand a polymeric carrier for the botulinum toxin. The carrier has thecharacteristic of high shear thinning so that it is injectable through a25 to 32 gauge needle.

The carrier in our formulation can be a high molecular weight,polymeric, hyaluronic acid. Hyaluronic acid is a major component of theextracellular matrices of soft tissues, such as the skin and muscle. Lowmolecular weight (about 1000 Daltons or less) hyaluronic acid can becleared rapidly from an intradermal or intramuscular location via thelymphatics. A higher molecular weight hyaluronic acid can have a longertissue residence time and be eliminated from a subdermal site throughlower local enzymatic process. We determined that the tissue residencytime of a hyaluronic acid in soft tissues can be increased by reducingboth lymphatic clearance and that this can be accomplished by increasingthe biological stability of the polymer, such as by using particularmethods and cross linkers to cross link a low molecular weighthyaluronic acid to thereby prepare a much higher molecular weight (1million Daltons or higher) hyaluronic acid, which has increasedbiological stability (meaning that the hyaluronic acid takes longer tobiodegrade), is biocompatible and functions as a depot which contains toprevent diffusion of the botulinum neurotoxin formulated with thehyaluronic acid in any amounts which exceed the amount of botulinumtoxin required to saturate adjacent neuromuscular junctions.

We determined that increasing the molecular weight of the polymericcarrier concomitantly increases the local botulinum neurotoxinconcentration at or near the site of injection. Additionally, wedetermined that increasing the degree of cross linking of the hyaluronicacid, or increasing the concentration of a hyaluronic acid in theformulation or increasing the molecular weight of the hyaluronic acidused in the formulation results in a longer tissue residence time of theformulation and reduce diffusion of the botulinum neurotoxin from theformulation to adjacent muscle groups and importantly also reducessystemic complications form the botulinum neurotoxin, as compared toinjections of aqueous formulations of the same concentration of the samebotulinum neurotoxin at the same subdermal injection site.

In our formulation a preferred hyaluronic acid has a molecular weight offrom about 10,000 to about 20 million Daltons. A preferred totalhyaluronic acid concentration of both crosslinked and uncrosslinkedcomponents in our formulation is from about 1 wt % to about 5 wt % crosslinked hyaluronic acid. Where a cross linked hyaluronic acid is used theactual crosslinking density (i.e. how many of the hyaluronic acidmonomers are actually linked to other hyaluronic acid monomers) is fromabout 5% to about 40%.

The hyaluronic acid used in our formulations is a natural component ofthe extracellular matrix of many mammalian tissues therefore providing abiocompatible carrier for the botulinum toxin. Additionally, thehyaluronic acid used in our improved formulations increases theviscosity of the formulation, as compared to the viscosity of abotulinum toxin formulation which does not comprise any hyaluronic acid,such as BOTOX®, DYSPORT® or MYOBLOC®. Where our formulations have a highviscosity they remain injectable through 25-32 gauge syringe needlesbecause of the high shear rate of the hyaluronic acid used in theformulation.

More important that the specific viscosity of our improved botulinumtoxin formulation is the depot characteristic of our formulations. Thus,the hyaluronic acid in the formulation act to provide a sustained ormodulated release of the botulinum toxin so that no or much reducedlocal and systemic botulinum toxin complications occur upon injection ofthe formulation. It is believed that the hyaluronic acid can act as atissue adhesive so that when hyaluronic acid is injected into a tissuesuch as a muscle diffusion and migration of the hyaluronic acid (andhence of the botulinum toxin as well) through fascial planes inminimized.

The tissue adhesion and therefore low tissue migration characteristic ofour formulations comprising hyaluronic acid enables the formulationincluding the botulinum toxin to remain largely at the injection site.Thus a botulinum toxin-hyaluronic acid formulation will have theadvantageous characteristic of low diffusion out of the botulinum toxinof the peripheral location, such as an intramuscular location (i.e. froman injected the small orbicularis muscle to treat hemifacial spasm).Hence, use of hyaluronic acid in our formulation can limit botulinumtoxin exposure to surrounding or adjacent non-target tissues, therebylimiting side effects (with regard to para-ocular botulinum toxinadministration) such as ptosis or visual impairment.

Another advantage of our formulation is that in order to have thebotulinum toxin released from a carrier solubilized contact with wateris required. The preferred hyaluronic acid used provides this through anability to become hydrated (absorb water).

Additionally, the hyaluronic acid used is a polymer that can becross-linked to varying degrees, thereby permitting alteration ofcharacteristics such as rate of hyaluronic acid migration for theperipheral location of administration, rate of active agent diffusionand migration out of the hyaluronic acid carrier.

In one embodiment, the present compositions have a viscosity of at leastabout 10 cps or at least about 100 cps, preferably at least about 1,000cps, more preferably at least about 10,000 cps and still more preferablyat least about 70,000 cps, for example, up to about 250,000 cps, orabout 300,000 cps, at a shear rate of 0.1/second. The presentcompositions are structured or have make-ups so as to be injectable intoa peripheral location of a human or animal body preferably through a 27gauge needle, more preferably through a 29 to 32 gauge needle.

Advantageously, the carrier and therefore our formulation as a viscosityat 25° C. of at least about 10 cps or at least about 100 cps or at leastabout 1000 cps, more preferably at least about 10,000 cps and still morepreferably at least about 70,000 cps or more, for example up to about200,000 cps or about 250,000 cps, or about 300,000 cps or more, at ashear rate of 0.1/second. The present drug delivery systems not onlyhave the relatively high viscosity as noted above but also have theability or are structured or made up so as to be effectively placeable,e.g., injectable, into a posterior segment of an eye of a human oranimal, preferably through a 27 gauge needle, or even through a 30 gaugeneedle.

The presently useful carrier preferably is a shear thinning component inthat as the present composition containing such a shear thinning carrieris passed or injected into the posterior segment of an eye, for example,through a narrow space, such as 27 gauge needle, under high shearconditions the viscosity of the viscous carrier is substantially reducedduring such passage.

Any suitable viscous carrier, for example, ophthalmically acceptableviscous carrier, may be employed in accordance with the presentinvention. The viscous carrier is present in an amount effective inproviding the desired viscosity to the drug delivery system.Advantageously, the viscous carrier is present in an amount in a rangeof from about 0.5 wt % to about 95 wt % of the drug delivery system. Thespecific amount of the viscous carrier used depends upon a number offactors including, for example and without limitation, the specificviscous carrier used, the molecular weight of the viscous carrier used,the viscosity desired for the present drug delivery system beingproduced and/or used and like factors.

Examples of useful viscous carriers include, but are not limited to,hyaluronic acid, carbomers, polyacrylic acid, cellulosic derivatives,polycarbophil, polyvinylpyrrolidone, gelatin, dextrin, polysaccharides,polyacrylamide, polyvinyl alcohol, polyvinyl acetate, derivativesthereof and mixtures thereof.

A dermal filler can also be used as the viscous carrier. Suitable dermalfillers for that purpose include collagen (sterile collagen is soldunder the trade names Zyderm, Zyplast, Cosmoderm, Cosmoplast andAutologen), Hylaform® (hyaluronic acid), Restylane® (hyaluronic acid),Sculptra™ (polylactic acid), Radiesse™ (calcium hydroxyl apatite) andJuvederm™. Juvederm™, available from Allergan, Inc. (Irvine, Calif.)comprises a sterile, biodegradable, non-pyrogenic, viscoelastic, clear,colorless, homogenized gel consisting of cross-linked hyaluronic acidformulated at a concentration of 24 mg/ml in a physiologic buffer.

The molecular weight of the presently useful viscous carrier can be in arange of about 10,000 Daltons or less to about 2 million Daltons ormore. In one particularly useful embodiment, the molecular weight of theviscous carrier is in a range of about 100,000 Daltons or about 200,000Daltons to about 1 million Daltons or about 1.5 million Daltons. Again,the molecular weight of the viscous carrier useful in accordance withthe present invention, may vary over a substantial range based on thetype of viscous carrier employed, and the desired final viscosity of thepresent drug delivery system in question, as well as, possibly one ormore other factors.

In one very useful embodiment, the carrier is a polymeric hyaluronatecomponent, for example, a metal hyaluronate component, preferablyselected from alkali metal hyaluronates, alkaline earth metalhyaluronates and mixtures thereof, and still more preferably selectedfrom sodium hyaluronates, and mixtures thereof. The molecular weight ofsuch hyaluronate component preferably is in a range of about 50,000Daltons or about 100,000 Daltons to about 1.3 million Daltons or about 2million Daltons. In one embodiment, the present compositions include apolymeric hyaluronate component in an amount in a range about 0.05% toabout 0.5% (w/v). In a further useful embodiment, the hyaluronatecomponent is present in an amount in a range of about 1% to about 4%(w/v) of the composition. In this latter case, the very high polymerviscosity forms a gel that slows particle sedimentation rate to theextent that often no resuspension processing is necessary over theestimated shelf life, for example, at least about 2 years, of the drugdelivery system. Such a drug delivery system can be marketed inpre-filled syringes since the gel cannot be easily removed by a needleand syringe from a bulk container.

The amount of the botulinum neurotoxin selected for local administrationto a target tissue according to the present disclosed invention can bevaried based upon criteria such as the location of the treatment, or thesolubility characteristics of the agent or formulation chosen, as wellas the age, sex, weight and health of the patient. For example, theextent of the area of muscle tissue influenced is believed to beproportional to the volume of neurotoxin injected, while the quantity ofthe relaxation effect is, for most dose ranges, believed to beproportional to the concentration of a Clostridial toxin administered.

Methods for determining the appropriate route of administration anddosage are generally determined on a case by case basis by the attendingphysician. Such determinations are routine to one of ordinary skill inthe art (see for example, Harrison's Principles of Internal Medicine(1998), edited by Anthony Fauci et al., 14^(th) edition, published byMcGraw Hill).

According to our invention, the botulinum toxin formulation is injectedlocally (e.g., intramuscular injection) into or in the vicinity of theintended treatment. In some embodiments, the neurotoxin can beadministered intradermally and/or subdermally. Further, the formulationcan be administered at one or multiple sites.

EXAMPLES

The following examples illustrate aspects of our invention.

Example 1 Low Viscosity Botulinum Toxin-Hyaluronic Acid Formulation

A botulinum toxin-hyaluronic acid formulation can be prepared asfollows. 1 gram of 1,4-butanediol diglycidyl ether (as cross linker) isadded to a 1-L aqueous solution containing 10 g hyaluronic acid (as theviscous carrier), adjusted to pH 12 while vortexing. The molecularweight of the uncross linked hyaluronic acid is about 500,000 Daltons.The reaction mixture is incubated at 60° C. for 45 minutes andneutralized with glacial acetic acid. The resulting crosslinkedhyaluronic acid can have a crosslinking density of about 10%. Tenmilligrams of the crosslinked hyaluronic acid is added to 1 mL of anaqueous solution containing 9 mg sodium chloride, 5 mg human albumin USPand 1,000 mouse LD₅₀ units of botulinum toxin type A complex. The finalsolution is lyophilized in a 6-mL type I glass vial. An aliquot of thelyophilized formulation containing 100 mouse LD50 units of toxin and 1mg of the crosslinked hyaluronic acid is reconstituted with 1 mL ofwater for injection (WFI) or with saline for injection. The resultingsolution has a hyaluronic acid concentration of about 0.1 wt % and aviscosity of about 300 cps.

Example 2 Low Viscosity Botulinum Toxin-Hyaluronic Acid Formulation witha Higher Hyaluronic Acid Concentration

Another botulinum toxin-hyaluronic acid formulation can be prepared asfollows. 1 gram of divinyl sulfone (as cross linker) is added to a 500mL aqueous solution containing 10 g hyaluronic acid (as the viscouscarrier) adjusted to pH 14 while vortexing. The molecular weight of theuncross linked hyaluronic acid is about 200,000. The reaction mixture isincubated at 40° C. for 8 hours and neutralized with glacial aceticacid. The resulting crosslinked hyaluronic acid can have a crosslinkingdensity of about 7%. Twenty milligrams of the crosslinked hyaluronicacid is added to 1 mL of an aqueous solution containing 9 mg sodiumchloride, 5 mg human albumin USP and 1,000 mouse LD₅₀ units of botulinumtoxin type A complex. The final solution is lyophilized in a 6-mL type Iglass vial. An aliquot of the lyophilized formulation containing 100mouse LD50 units of toxin and 1 mg the crosslinked hyaluronic acid isreconstituted with 1 mL of water for injection (WFI) or with saline forinjection. The resulting solution has a hyaluronic acid concentration ofabout 0.5 wt % and a viscosity of about 300 cps. Since the amount ofcross linking is decreased in the Example 2 formulation theconcentration of the hyaluronic acid in the formulation is increased toprovide the same viscosity as the Example 1 formulation

Example 3 High Viscosity Botulinum Toxin-Hyaluronic Acid Formulation

A high viscosity botulinum toxin-hyaluronic acid formulation can havethe ingredients shown in Table 1 below.

TABLE 1 Ingredient Amount Botulinum toxin type A 100 units Sodiumhyaluronate (polymeric) 2.5% (w/v) Sodium chloride 0.63% (w/v) dibasicsodium phosphate, 0.30% (w/v) heptahydrate Monobasic sodium phosphate,0.04% (w/v) monohydrate Water for Injection q.s. Viscosity at shear rate170,000 ± 25% cps 0.1/second at 25° C.

Preferably the botulinum toxin used is BOTOX®, which is a lyophilized,powdered form of a botulinum toxin type A stabilized with albumin andsodium chloride. The formulation is made by first reconstituting thepowdered botulinum toxin with isotonic saline (sodium chloride) (therebymaking part 1). The sodium hyaluronate can be purchased as a sterilepowder or sterilized by filtering a dilute solution followed bylyophylization of the sodium hyaluronate to yield a sterile sodiumhyaluronate powder. The sterile sodium hyaluronate is dissolved in waterto make an aqueous concentrate (thereby making part 2). Part 1 and part2 are then mixed together to provide the ingredient concentrations shownin Table 1. Thus, the reconstituted botulinum toxin is mixed with thesodium hyaluronate concentrate to form a gel, and the phosphate buffersare then added. Water is added q.s. (quantum sufficit, as much assuffices, in this case as much as is required to prepare the homogenousmixture, dispersion, gel or suspension) and the mixture is mixed untilhomogenous. The formulation so prepared (or an aliquot thereof) can belocally injected using a 27 gauge or a 30 gauge needle to provide adesired therapeutic or cosmetic effect.

The sodium hyaluronate powders used in the formulation has a watercontents in a range of about 4% to about 20%, preferably about 4% toabout 8%, by weight. Because the formulation has a density of about 1gm/ml, the percentages set forth herein as being based on weight pervolume (w/v) can also be considered as being based on weight per weight(w/w).

The formulation of Examples 3 uses a sufficient concentration of highmolecular weight, sodium hyaluronate so as to form a gelatinous plug ordrug depot upon local, subdermal injection of the formulation.Preferably the average molecular weight of the hyaluronate used is lessthan about 2 million, and more preferably the average molecular weightof the hyaluronate used is between about 1.3 million and 1.6 million.Since sodium hyaluronate solutions comprised of high molecular weighthyaluronic acid are subject to dramatic shear thinning, theseformulations are easily injected through 27 gauge or even 30 gaugeneedles. Low molecular weight and cross-linked hyaluronic acids exhibitlittle if any shear thinning and can be useful to prepare formulationswithin the scope of our invention, as low viscosity formulations.

The most preferred viscosity range for the formulation is 140,000 cps to280,000 cps at a shear rate 0.1/second at 25° C.

The formulation is formulated using excipients that are fullybiocompatible (i.e. non-toxic) and is buffered at physiological pH bythe low concentration of sodium phosphate salts; rendered isotonic withsodium chloride, and use Water for Injection, USP.

Example 4 In Vivo Diffusion of Biologic-Hyaluronic Acid Formulations

We developed an animal model to assess in vivo subdermal residency timeof a biologic-hyaluronic acid formulation. Botulinum toxin is abiologic. Using this model we were able to examine localization of thebiologic-hyaluronic acid formulation in a specific muscle and theability of the polymeric formulation containing a crosslinked hyaluronicacid to increase the residency time of the biologic in the muscle. Inthis Example we used albumin as a surrogate for botulinum toxin in thehyaluronic acid formulation prepared.

The rat gastrocnemius muscle consists of two distinct muscles, thetripennate gastrocnemius lateralis (MGL) and the unipennategastrocnemius medialis (MGM) (see FIG. 1). We examined the movement of abiologic compound injected into the MGL and quantified the amountidentified in the adjacent MGM muscle using high resolution dynamic MRI.The biologic compound was a Albumin-Gadolinium complex with a molecularweight of about 65,000 Daltons (obtained from Biopal, Worcester, Mass.)and the injection site was in the MGL muscle, with the needle placed 2cm from the heel, lateral to the tibia with an injection depth of 4 to 5mm (see FIG. 2).

A polymeric formulation using crosslinked hyaluronic acid was made usingthe Albumin-Gadolinium complex which had a final concentration of 2×10⁻⁴M in the formulation. The crosslinked hyaluronic acid used was Juvederm™(Allergan, Irvine, Calif.). Juvederm™ is a sterile, biodegradable,non-pyrogenic, viscoelastic, clear, colorless, homogenized gelconsisting of cross-linked hyaluronic acid formulated at a concentrationof 24 mg/ml in a physiologic buffer.

A 5 microliter injection of the hyaluronic acid-Albumin-Gadoliniumcomplex was performed in the MGL muscle of the right leg, and the leftleg had a similar injection of the same formulation without thehyaluronic acid. The primary outcome measure was the amount ofAlbumin-Gadolinium that diffused to the MGM muscle in each leg.

Results from this experiment showed that there was rapid spread of theAlbumin-Gadolinium complex in the left calf with cross-over to the MGMmuscle within the first hour (see FIG. 3). In the right leg, theinjected hyaluronic acid-Albumin-Gadolinium complex stayed primarilywithin the injected depot area in the MGL muscle and there was minimalsignal present in the adjacent MGM muscle. These results indicate that ahyaluronic acid based formulation can be used limit the diffusion of abiologic compound (such as a botulinum toxin) from the injected musclesite.

Example 5 Botulinum toxin-Hyaluronic Acid Formulation for TreatingCervical Dystonia

A male patient age 45 suffering from A male suffering from cervicaldystonia as manifested by spasmodic or tonic contractions of the neckmusculature, producing stereotyped abnormal deviations of the head, thechin being rotated to one side, and the shoulder being elevated towardthe side at which the head is rotated, is treated by injection of theExample 1 formulation comprising about 75-125 units of the botulinumtoxin type A. Within 3-7 days, the symptoms are substantiallyalleviated, that is the patient is able to hold his head and shoulder ina normal position.

EMG recording indicates no local diffusion of the botulinum toxin out ofthe injected muscle area is detected as no paralysis of adjacent musclesoccurs. No diffusion of the botulinum neurotoxin into deep neck musclesis indicated as no weakness of the pharyngeal and esophageal musclesresults and the patient has no difficulty swallowing (dysphagia) at anytime after the injection. Nor does any dysarthria occur.

Example 6 Botulinum Toxin-Hyaluronic Acid Formulation for TreatingBlepharospasm

The Example 2 formulation comprising about 1-5 units of the botulinumtoxin per muscle is intramuscularly injected into a patient to treat hisblepharospasm. The formulation is injected into the lateral pre-tarsalorbicularis oculi muscle of the upper lid and the lateral pre-tarsalorbicularis oculi of the lower lid.

No diffusion of the botulinum neurotoxin into the deeper levator muscleis observed. Additionally the patient does not experience any ptosis orbrow ptosis or visual field impairment. EMG recording indicates nodiffusion of the botulinum toxin out of the orbicularis muscle into thefrontalis muscle, the deeper rectus muscles or into the zygomaticusmajor muscle. Notably, the patient does not experience any medialectropion, chronic tearing, double vision or asymmetric facialexpression.

Example 7 Botulinum Toxin-Hyaluronic Acid Formulation for TreatingStrabismus

The Example 3 formulation comprising about 1-5 units of BOTOX® is usedto treat strabismus by local injection of the extraocular (medialrectus) muscles of a patient with strabismus. The number of units of thebotulinum toxin injected can vary based upon both the size of the muscleto be injected and the extent of muscle paralysis desired (i.e. amountof diopter correction desired).

The patent experiences no esotropia, nor any double vision. UnalteredEMG (electromyographic) recording shows that no botulinum toxin hasdiffused into the muscle cone and that the other recti leading has notbeen paralyzed.

Example 8 Botulinum Toxin-Hyaluronic Acid Formulation for TreatingHeadache

A patient with migraine is pericranially injected (injectedsymmetrically into glabellar, frontalis and temporalis muscles) withsufficient Example 1, 2 or 3 formulation to comprise an injection of 25U of the botulinum toxin. The patient shows significant benefit as themigraine subsides within a day or two. EMG recording shows that nobotulinum toxin has diffused from the injected muscles.

Example 9 Botulinum Toxin-Hyaluronic Acid Formulation for Cosmetic Use

A patient with prominent glabellar lines is injected with sufficientExample 1, 2 or 3 formulation to comprise an injection of about 30 unitsof the botulinum toxin. The formulation is injected intramuscularly with10 units into the procerus muscle and 10 units injected intramuscularlyinto each corrugator supercilii muscle).

No diffusion of the botulinum neurotoxin into non-injected muscle isobserved, using EMG. The patient does not experience any ptosis or browptosis or any asymmetric facial expression.

Advantages of our formulations include increasing residency of thebotulinum neurotoxin will increase the efficiency of deactivating nerveterminals in a given muscle and potentially increase the duration of themuscle paralysis. Additionally, increasing the residency time of thebotulinum neurotoxin in the muscle tissue can also reduce exposure ofthe botulinum neurotoxin to the lymphatic system. It is know thatantibody production to an antigen requires drainage of the antigen toregional lymph nodes thereby exposing the antigen to the immune system.Antibodies to the antigen are produced, and in the case of a biologic,such as a botulinum toxin, neutralizing antibodies can form which may beone factor leading to ‘neurotoxin resistance’ and poor therapeuticresponses following injection. A botulinum neurotoxin is not stablelong-term in muscle tissue and require an acidic environment, preferablyin the pH range around 5, to prevent degradation. Therefore, increasingtissue residency times, will allow for local degradation of thebotulinum neurotoxin so that the lymphatic systems does not haveexposure to the parent species and neutralizing antibodies may not beproduced.

All references, articles, patents, applications and publications setforth above are incorporated herein by reference in their entireties.

Accordingly, the spirit and scope of the following claims should not belimited to the descriptions of the preferred embodiments set forthabove.

1. A pharmaceutical composition comprising a botulinum neurotoxin and aviscous carrier for the botulinum neurotoxin.
 2. The pharmaceuticalcomposition of claim 1, wherein the viscous carrier is selected from thegroup of viscous carriers consisting of hyaluronic acid, carbomer,polyacrylic acid, cellulose polycarbophil, polyvinylpyrrolidone,gelatin, dextrin, polysaccharide, polyacrylamide, polyvinyl alcohol,polyvinyl acetate, chitosans, algenates and derivatives and mixturesthereof.
 3. The pharmaceutical composition of claim 2 wherein theviscous carrier is a hyaluronic acid.
 4. The pharmaceutical compositionof claim 3 wherein the viscous carrier is a hyaluronic acid is anon-cross linked hyaluronic acid.
 5. The pharmaceutical composition ofclaim 3 wherein the hyaluronic acid is a cross linked hyaluronic acid.6. The pharmaceutical composition of claim 3 wherein the hyaluronic acidis polymeric hyaluronic acid with a molecular weight between 10,000Daltons and 20 million Daltons.
 7. The pharmaceutical composition ofclaim 4 wherein the concentration of hyaluronic acid in thepharmaceutical composition is between 1 wt % and 10 wt %.
 8. Thepharmaceutical composition of claim 5 wherein the concentration ofhyaluronic acid in the pharmaceutical composition is between 0.1 wt %and 1 wt %.
 9. The pharmaceutical composition of claim 4 wherein theviscosity of the pharmaceutical composition is between 1000 cps and300,000 cps at 25° C., at a shear rate of 0.1/second.
 10. Thepharmaceutical composition of claim 5 wherein the viscosity of thepharmaceutical composition is between 100 cps and 1,000 cps at 25° C.,at a shear rate of 0.1/second.
 11. A pharmaceutical compositioncomprising a botulinum neurotoxin and a cross linked, polymeric,hyaluronic acid carrier for the botulinum neurotoxin, wherein thepolymeric hyaluronic acid has a molecular weight between 10,000 Daltonsand 20 million Daltons, the concentration of the polymeric hyaluronicacid in the pharmaceutical composition is between 0.1 wt % and 1 wt %and the viscosity of the pharmaceutical composition is between 100 cpsand 1,000 cps at 25° C., at a shear rate of 0.1/second.
 12. Thepharmaceutical composition of claim 11 wherein the botulinum neurotoxinis a botulinum neurotoxin type A.
 13. The pharmaceutical composition ofclaim 11 wherein the polymeric hyaluronic acid has a molecular weightbetween 10,000 Daltons and 1 million Daltons.
 14. The pharmaceuticalcomposition of claim 11 wherein the concentration of the polymerichyaluronic acid in the pharmaceutical composition is between 0.1 wt %and 0.5 wt %.
 15. The pharmaceutical composition of claim 11 wherein theviscosity of the pharmaceutical composition is between 100 cps and 500cps at 25° C., at a shear rate of 0.1/second.
 16. A pharmaceuticalcomposition comprising a botulinum neurotoxin type A and a cross linked,polymeric, hyaluronic acid carrier for the botulinum neurotoxin, whereinthe polymeric hyaluronic acid has a molecular weight between about10,000 Daltons and about 1 million Daltons, the concentration of thepolymeric hyaluronic acid in the pharmaceutical composition is between0.1 wt % and 0.5 wt % and the viscosity of the pharmaceuticalcomposition is between 100 cps and about 500 cps at 25° C., at a shearrate of 0.1/second.
 17. A method for treating a disease or condition ina human patient by administering to the patient a pharmaceuticalcomposition comprising a botulinum neurotoxin and a viscous carrier forthe botulinum neurotoxin, wherein the patient experiences significantlyfewer complications due to the botulinum toxin than occur uponadministration of a botulinum toxin containing pharmaceuticalcomposition which does not comprise a viscous carrier.
 18. The method ofclaim 17, wherein the administering is carried out by local subdermalinjection of the pharmaceutical composition.
 19. The method of claim 17,wherein the disease or condition is selected from the group of diseasesand conditions consisting of dystonia, cervical dystonia, blepharospasm,strabismus, spasticity, movement disorder, headache, migraine,hyperhydrosis, overactive bladder, prostate disorder, articularpathology, arthritis, facial wrinkles, and glabellar lines.
 20. Themethod of claim 17, wherein the complications are local complicationsselected from the group of local complications consisting of ptosis,brow ptosis, visual field impairment, double vision, ectropion, tearing,asymmetric facial expression, dysphagia, and muscle weakness.
 21. Themethod of claim 17, wherein the complications are systemic complicationsselected from the group of system complications consisting ofrespiratory distress, generalized weakness, dry mouth, nausea, headache,constipation and vertigo.
 22. The method of claim 17, wherein thepatient experiences no complications during any ten day period up to sixmonths after the administration.
 23. The method of claim 17, wherein thepatient experiences during any ten day period up to six months after theadministration a complication which persists, as reported by thepatient, for only 10% to 50% of the period of time the same complicationis experienced by the patient upon administration of a botulinum toxinformulation which is injected into the patient at the same location, totreat the same disease or condition, and which contains the same amountof the botulinum toxin, but which does not comprise a viscous carrieracid.
 24. The method of claim 17, wherein the viscous carrier isselected from the group of viscous carriers consisting of hyaluronicacid, carbomer, polyacrylic acid, cellulose polycarbophil,polyvinylpyrrolidone, gelatin, dextrin, polysaccharide, polyacrylamide,polyvinyl alcohol, polyvinyl acetate, chitosans, algenates andderivatives and mixtures thereof.
 25. The method of claim 24 wherein theviscous carrier is a hyaluronic acid.
 26. A process for making apharmaceutical composition, the process comprising the steps ofpreparing a pharmaceutical composition comprising a botulinum neurotoxinand a viscous carrier for the botulinum neurotoxin by mixing togetherthe botulinum neurotoxin and the viscous carrier.
 27. A product by theprocess of claim 26.